Ubiquinone vs. Ubiquinol: Which Type of CoQ10 is Better?

You may have heard the terms ubiquinone and ubiquinol when referring to CoQ10. They sound the same, but are they? This guide will outline the differences between the two and discuss which is the best CoQ10 supplement for fertility.

By Dr. Kenosha Gleaton

Coenzyme Q10, also known as CoQ10, is a popular antioxidant recommended for a variety of conditions from infertility to heart health to migraines. [1] Fun fact: CoQ10 is not a vitamin! It’s a nutrient that exists in almost every cell of the human body. In your body, CoQ10 shifts back and forth between two states in a continuous cycle: ubiquinone and ubiquinol. CoQ10 supplements on the market will be one of these two forms.

What’s the Difference Between Ubiquinol and Ubiquinone?

Both ubiquinol and ubiquinone are true forms of coenzyme Q10, and the terms are often used interchangeably. From a chemistry standpoint, ubiquinol is the reduced form of CoQ10, whereas ubiquinone is the oxidized form. [2] 

Remember that CoQ10 occurs naturally in the body, where it shifts between its ubiquinone and ubiquinol form in a continuous cycle. [3] When you take a ubiquinone supplement, such as our CoQ10 gummies, your body converts it to ubiquinol and back again. So regardless of what form of CoQ10 you take, your body will convert it to the other form as needed. [3] 

Ubiquinone was the only version of CoQ10 on the market until 2007, when the developer of the patented technology for producing the active form of CoQ10 commercialized (and trademarked) ubiquinol. Because of this, ubiquinol is more expensive. Some people assume that because it’s more expensive, it is better. But there’s no compelling data to support that claim. 

What Foods Are High in Ubiquinol?

Some of the most well-known ubiquinol food sources are fatty fish, including salmon, tuna, and sardines, as well as organ meats and whole grains. [3] The body uses both forms of CoQ10 and shifts between them regularly, so any food sources high in CoQ10 can provide your body with ubiquinol as well as ubiquinone. [10]

Who Should Not Use Ubiquinol?

Ubiquinol or CoQ10 supplementation may not be right for everyone. If you have one of the following conditions or belong to one of the following groups, you should take additional precautions before supplementing with CoQ10 [11]:

• Liver or kidney disease
• Diabetes
• History of hypoglycemic episodes
• Breastfeeding parents
• Children and infants

What Vitamins Should I Not Take With CoQ10?

It’s best to speak directly with a healthcare provider for insight on the supplements and vitamins you’re taking. That being said, data shows that some medications may interact poorly with CoQ10. These include blood thinners, blood pressure medications, and chemotherapy medications. [12] 

Which is Better: CoQ10 Ubiquinol or Ubiquinone?

Research has not proven one form of coenzyme Q10 is better than the other, and given the body naturally converts between the two forms, it is unlikely that there is a big difference between them.

It is important to note that ubiquinone has been on the market longer and has been used in the vast majority of clinical trials of CoQ10 (including those studying the benefits of CoQ10 for fertility). 

Both forms of CoQ10—ubiquinol and ubiquinone—are considered safe, with few side effects. 

Which Form of CoQ10 is More Bioavailable?

The bioavailability of a supplement is the proportion which reaches systemic circulation and can be used by the body. [4] Both ubiquinone and ubiquinol have high bioavailability.

One study found no significant difference in the absorption of various CoQ10 formulations and that CoQ10 appeared in the blood as ubiquinol, even if it was consumed as ubiquinone. [5] Another study of seven different supplement formulations found large differences in the bioavailability of formulations, with the best absorbable formulations being soft-gel capsules containing either ubiquinone or ubiquinol. [5] 

Is Ubiquinol Safe to Take Daily? 

Ubiquinol is likely safe to be taken every day. [13] There is a very low risk of experiencing any toxic effects from taking CoQ10, even in large doses of up to 1,200mg/day. [13] 

There are potential side effects associated with most supplements, including CoQ10. [14] You may notice digestive upset, headaches, fatigue, rashes, or other side effects. [14] Always speak to your provider about any supplements and medications you’re taking or considering. 

CoQ10 for Fertility

 Coenzyme Q10 supplements can benefit both male and female fertility outcomes.  

Female Fertility

Female fertility typically declines after the age of 35. [6] This decline is primarily due to an age-related decrease in egg quality that typically occurs in many women. In the aging process, CoQ10 concentration in parts of the body (including female eggs) declines. [7]  Therefore, some fertility doctors recommend CoQ10 supplementation for women over 35 to make up for the natural decline that may contribute to decreased egg quality. 

The data on CoQ10 is emerging, and there haven't been randomized double-blind clinical trials focusing on female fertility yet. Studies that have been conducted so far suggest that, in women over 35, supplementing with CoQ10 may lead to improved egg quality, improved embryo quality, and improved reproductive health and pregnancy outcomes. [8] Another 2017 study concluded that high CoQ10 levels in follicular fluid (fluid that surrounds the ovum in the ovary) is associated with higher pregnancy rates. [5]

Male Fertility

Prenatal vitamins and other supplements are not only for a woman's reproductive health. In addition to considering taking prenatal vitamins for men, taking CoQ10 may support male fertility parameters, specifically by improving sperm motility. Poor sperm motility means that the sperm do not swim properly and may not be able to reach the egg. Sperm is extremely susceptible to oxidative stress, which can cause sperm damage. Antioxidants combat free radical and the oxidative stress they cause. As a potent antioxidant, CoQ10 has been shown in clinical trials to improve male fertility parameters like sperm motility.

In a meta-analysis published in 2018, researchers concluded that CoQ10 supplementation resulted in better sperm motility along with improved sperm concentrations and sperm count. [9] Check out our Guide to Male Fertility for more nutrition and lifestyle guidance for men trying to conceive.

The benefits of CoQ10 supplements are for both egg and sperm health. However, deciding which supplement is best can depend on a few factors, but both forms are considered safe, with few side effects. 

Key Takeaways

• CoQ10 is a natural antioxidant, and both forms of CoQ10—ubiquinol and ubiquinone —are considered safe with few side effects.
• More clinical trials have been conducted with ubiquinone supplements than ubiquinol supplements.
• Ubiquinone and ubiquinol shift from one form to the other inside the body.
• In terms of absorption and bioavailability, there is no clear cut difference between ubiquinone and ubiquinol.
• Ubiquinol is trademarked, patented, and produced by one private company, and costs more to manufacture than ubiquinone.
• Any supplement routine should be discussed with your physician who can give further guidance on what is best for you.

References:

1. Coenzyme Q10. Mayo Clinic. November 2020. URL. 
2. Coenzyme Q10. Oregon State Univeristy. Reviewed May 2018. URL. 
3. Saini R. Coenzyme Q10: The essential nutrient. J Pharm Bioallied Sci. 2011;3(3):466-467. doi:10.4103/0975-7406.84471
4. Price G, Patel DA. Drug Bioavailability. [Updated 2022 Jun 23]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK557852/
5. Akarsu S, Gode F, Isik AZ, Dikmen ZG, Tekindal MA. The association between coenzyme Q10 concentrations in follicular fluid with embryo morphokinetics and pregnancy rate in assisted reproductive techniques [published correction appears in J Assist Reprod Genet. 2017 May;34(5):607]. J Assist Reprod Genet. 2017;34(5):599-605. doi:10.1007/s10815-017-0882-x
6. GBD 2017 Population and Fertility Collaborators. Population and fertility by age and sex for 195 countries and territories, 1950-2017: a systematic analysis for the Global Burden of Disease Study 2017 [published correction appears in Lancet. 2019 Jun 22;393(10190):e44]. Lancet. 2018;392(10159):1995-2051. doi:10.1016/S0140-6736(18)32278-5
7. Barcelos IP, Haas RH. CoQ10 and Aging. Biology (Basel). 2019;8(2):28. Published 2019 May 11. doi:10.3390/biology8020028
8. El Refaeey A, Selem A, Badawy A. Combined coenzyme Q10 and clomiphene citrate for ovulation induction in clomiphene-citrate-resistant polycystic ovary syndrome. Reprod Biomed Online. 2014;29(1):119-124. doi:10.1016/j.rbmo.2014.03.011
9. Salas-Huetos A, Rosique-Esteban N, Becerra-Tomás N, Vizmanos B, Bulló M, Salas-Salvadó J. The Effect of Nutrients and Dietary Supplements on Sperm Quality Parameters: A Systematic Review and Meta-Analysis of Randomized Clinical Trials. Adv Nutr. 2018;9(6):833-848. doi:10.1093/advances/nmy057
10. Pravst I, Rodríguez Aguilera JC, Cortes Rodriguez AB, et al. Comparative Bioavailability of Different Coenzyme Q10 Formulations in Healthy Elderly Individuals. Nutrients. 2020;12(3):784. Published 2020 Mar 16. doi:10.3390/nu12030784
11. Sood B, Keenaghan M. Coenzyme Q10. [Updated 2022 Jan 19]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK531491/
12. Coenzyme Q10. National Center for Complementary and Integrative Health. January 2019. https://www.nccih.nih.gov/health/coenzyme-q10
13. Shults CW, Oakes D, Kieburtz K, et al. Effects of coenzyme Q10 in early Parkinson disease: evidence of slowing of the functional decline. Arch Neurol. 2002;59(10):1541-1550. doi:10.1001/archneur.59.10.1541
14. Coenzyme Q10. Mayo Clinic. August 2023. https://www.mayoclinic.org/drugs-supplements-coenzyme-q10/art-20362602